Measured-service automatic telephone system



June 19, 1923. 1,459,229

T. G. MARTIN MEASURED SERVICE AUTOMATIC TELEPHONE SYSTEM Filed May 15 1919 3 Sheet Sheet 1 g a g; 1

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T. G. MARTIN MEASURED SERVICE AUTOMATIC TELEPHONE SYSTEM Filed May 15 1919 3 Sheets-Sheet 2 June -19, 1923.

T. G. MARTIN MEASURED SERVICE AUTOMATIC TELEPHONE SYSTEM Filed May 15 1919 5 Sheets-Sheet 5 Patented Jane is, ieae.

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I TALBOT G. MARTIN, OF CHICAGO, ILLINOIS, ASSIGNOR T0 AUTOMATIC ELECTRIC COM- P, 0E CHICAGO, ILLINOIS,

A CORPORATION OF ILLINOIS.

MEASURED-SERVICE AUTOMATIC TELEPHONE SYSTEM.

Application aiea May 15,

To all whom it may concern:

Beit known that I, TALBOT G. MARTIN, a citizen of the United States of America, and a resident of Chicago, in the county of Cook and State of Illinois, have invented certain new and useful Improvements in Measured- Servi'ce Automatic Telephone Systems.

My inventionv relates in general to an improved means for automatically controlling a measured service device, and more particularly to improved circuits and devices for automatically controlling a pay station or coin collector in an automatic telephone system.

The main object of this invention is to provide an improved means for operating a coin collector of the coin first type, when calls A are made from an automatic telephone through automatic switches, or by an operator through an automatic switch to such an automatic telephone.

Other objects are to provide reliable and accurate means for collecting or refunding a .coin with such efiiciency and accuracy that there will be no chance for a subscriber to either inadvertently or maliciously make a call for which a charge is required without being properly charged for such call.

It is to be understood that any standard type of coin collector or pay station device, such as that shown in U. S. Letters Patent No. 1,043,219 granted November 5,1912 to OF. Forsberg, may be used with this invention which is adapted to receive a coin deposited before a call is initiated and having a chute for returningthe coin if the call is unsuccessful, and for collecting the coin if the call is successful. I have shown a chute and other parts only diagrammatically as my invention has to do principally with the circuits and method of controlling the collecting and refunding.

The feature of my inventionwhich relates tor the collection or refunding of the coin 'by an operator through an automatic switch is not claimed herein, but is claimed in a di-v .visionaliapplication, Serial No. 604,755,

filed December 4, 1922.

In theaccompanying drawings: Fig. 1 shows a calling station A of automatic type being'a pa station and havin access by means of the ine switch 0 to t lines leading to first selectors; Inserted in 1919. Serial no. ear I332. I

these trunk lines are groups of controlling i line switch C terminates, and a connectorswitch H accessible to the selector E.

. F 1g. 3 shows a manual calling line B. A cord circuit F for handling calls therefrom, and a special connector switch H which is accessible to the cord circuit F for calls from manual lines such as B to any of the automatic lines such as A (Fig. 1) ,and having means for reversing the charge to assess the toll upon the called subscriber when desired.

t Fig. 4 shows a modification of the invenion.

I will first explain the operation of the system when a call is setup from a pay statiQnline such as A (Fig. 1) to a line similar :to A, accessible to the switch. H (Fig. 2)

cut the spring 10 is controlled by the coin when deposited to open the springs 11 and 12 and to close contact of thesprings 10 and 11. The springs 10, 11 and 12 are also controlled by theoperation of the magnet 13 in either direction in the same manner, that is, these springs are locked in operated position by a coin and are unlocked by the operation of the magnet 13. The springs 20 are opened when the receiver is removed to open one point in the circuit of magnet 13. The

springs 14 to 18 inclusive, are controlled by a bushing on the calling device in such a manner that as the dial is moved off normal the springs 15 and 17 move to their alternate positions and are restored when the dialreturns to normal. The calling device may be of the type disclosed in Patent No. 1,279,352, issued to A. E. Keith, September 17, 1918. The coin being deposited closes the springs circuit of relay 10 and 11 in contact thereby connectingthe magnet 13, through springs 17 and 18 and springs 10 and 11 tothe talking circuit and also removing a shunt from around the impulse springs at springs 11 and 12, so as to render said springs 7 efiective to interrupt the line circuit when the calling device is turned subsequently.

The operation of the line relay 2 causes the operation of the line switch C to automatically select an idle trunk line leading to a selector E (Fig. 2) in the usual manner by closing a circuit direct rom private wiper 20' to magnet 21 and also preparing.

a series circuit for switching relay 22 in series with magnet 21 so .that when an.idle trunk line is reached relay 22 will energize to disconnect the relay 2 from the line circuit and extend the-line of substation A to the selected idle trunk. Associated with each trunk leading to the selectors E is a group of relays such as D, the function of which is to control the collection or refunding of the coin at the calling station. As relay 22 energizes a circuit is completed for the line relay 23 of the selector E as follows: battery through the upper winding of said relay, springs 24 and 25, upper windin of relay 27 and-resistance 26 in multiple, re ay 28 and resistance 29 in multiple, springs 30 and 31, springs 32, springs 33 and 34, to and through the substation A, and back over the other side of the line through springs 35 and 36, springs 37, springs 38 and 39, springs 40 and 41, and lower winding of relay 23 to ground. Relay 23 energizes and closes the, circuit of slow relay 42-to ground the release trunk and prepare the circuit'for the vertical magnet 43. The circuits of the selector E and connector H are of well known standard type and only a general de scription will be given of their operation.

it will be noticed that relays 27 and 28 were included in the above traced circuit with the relay 23. Relay 27 does not ener- 'ze in this circuit as it is an electro polarlzed relay which requires the energization of both windings in the same direction to" assist each other. Relay 28, however, energizes and closes the circuit of slow relay 44' and relay 45. Relay 45 operates to open the springs 46 and 47 and'relay 44 ope-rates to close-the circuit of relay 48 which closes the sprin s 49 and 50, thereby energizing relay 51. elay 44 also closes the circuit of the lower polarizing. winding of relay 27. Relay 430pens the springs 52 and 53, closes springs 52 and 39, opens springs 39 and 38, opens sprin? 30 and 3l,and closes springs 30 and 60. elay 51 at the same time opens the springs 35 and 36, closes springs 35 and 54, closes springs 55, closes springs 56 in the 57, which relay does not, however, energize at this time, due. to its circuit being open at the springs 47, and also opens springs 33 and 34 and closes springs 34 and 61. The. line circuit it will be seen now passes. through the springs 34- and 61, springs 60 and 30, relay 28 andv resistance 29 in multiple, and relay 27 and resistance 26 in multiple in the upper trunk conductor. and through springs 35 and 54 and springs 52 and 39 of the lower trunk conductor.

The subscriber now operates his calling device for the first digit of the called number to operate the selector E (Fig. 2). As soon as the calling device is moved 1 off normal the springs 14 and 15 make contact, springs 15 and 16 are opened, and springs 17 and 18 in the circuit of magnet 13 are opened. The coin having been deposited to remove the short circuit as pointed out be-- 'fore, the calling device will control the line A magnet 63 and interrupter relay 64 to step the wipers of selector.E to an idle trunk leading to a connector H. As soon as such idle trunk is found, relay 65 energizes and is locked energized to cut off the line relay 23 and cut the extended line circuit through to the line relay 66 of connector H.

The callingdevice is now operated for the next digit of the called number. Relay 66 is operated in accordance with this digit to'control the vertical magnet 67 and slow relays 68 and 69. Relay 69 holds groumd on the release trunk and prepares the circuit of the vertical magnet which in turn steps the wipers of the switch to,a level of the bank in which the contacts of the called line are located. 'As soon as the impulses of this digit cease relay 68 falls back and prepares the circuit of relay 70 and rotary magnet 71, so that as the calling device is again operated the line relay 66 controls the circuit of the rotary magnet 71 to step the wipers into engagement with the called line. Relay 70 remains energizedfor a short interval after the rotary impulses cease to hold the private wiper connected tobusy relay 72 so that this relay may operate to give a busy signal if the called line is busy. When The energization of relay 75 causes the connections of the line relay 66 to the talking circuit to be reversed, thereby reversing the direction of 'the'current flow in the trunk and line circuit to the calling subscriber. The reversal ofcurrent in the trunk circuit menace to the calling subscriber causes both wind ings of the relay 27 to assist each other and relay 27 therefore energizes and is held energized by its lower winding alone, the upper winding and the resistance 26 being shorted out by the springs 76. Thesprings 77 also short out a part of resistance 29 to allow a better path for voice currents. The energization of relay 27 closes the springs 78 and 79 to connectthe high voltage positive battery K in series with the lamp 80 through springs to the spring 53 which is now disengaged from the spring 52. Relay 28 remains energized to hold the various relays energized and conversation may now proceed over the heavy conductors shown.

When the conversation is' completed the connection is released by the restoration of the receivers at the calling and called stations. Line relay 66 of the connector deenergizes, opens the circuit of slow relay 69 which removes ground at that point from the release trunk and closes a point in the circuit of the release magnet of the connector which is closed as soon as the called man hangs up. As soon as the calling subscriber hangs up it will be seen that the relay 28, which is in series with the line circuit, will fall back and open the circuit of relays 4d and 45. Relay 45 will fall back before relay 44c and close a circuit through springs 47 and 56 for slow relay 57. Relay 45 also applies ground to the release trunk conductor at spring 46 and its back contact and through springs 49 which are held closed by relay 48. This occurs, it will be understood, before the previously mentioned removal of ground from the release trunk conductor at the connector. Relay 57 holds ground direct on the release'trunk at springs 58 and 59 to revent the line switch C from releasing be ore the coin is collected and.opens the springs .32 and 37 in the talking circuit to prevent any connection of the high voltage battery to the selector. The opening of these springs in the talking circuit also prevents any short circuit or shunt circuit around the magnet 13 of the coin collector and cuts ofi any leak of the operating current. Relay 57 also supplies an additional holding ground to the relay 27 to keep said relayenergized. After a short interval relay 44 also falls back and opens the circuit of relay 48 which falls back to open the springs 60 and 30 and springs 52 and 39 in the talking circuit, and to remove, ground from the release trunk conductor extending to the selector E, so as to allow the selector E to release. Relay 48 also closes the springs 52 and 53 in the high voltage battery circuit which now is completed for an instant and extends from-battery K and lamp 80, through springs 79 and 78, springs '55, held closed b relay 51,

springs 53 and 52, springs an 35, to the.

calling line and through springs 7 of the calling device, springs 11 and 10 of the coin controlled springs, springs 17 and 18 and springs 20 in multiple, and throu h the magnet 13 to ground. The battery is of high potential and is of such polarity as to operate the magnet 13 to release the coin and direct it into the collect chute, and the springs 10, 11 and 12 are restored to normal. Relay 51, of course, deenergizes a short time after its circuit is. opened by relay '48 and opens the circuit of relay 57 and also restores the line circuit to normal and opens the springs 55in :the high voltage battery circuit. Relay 57, upon deenergizing, opens the circuit of the winding of relay 27 and also removes round from the release trunk to th e line switch C to allow said switch to release in readiness for the next call. lit will be seen that the springs 20, which are closed upon the receiver being replaced, place a shunt around springs 17 and 18, thereby preventing the subscriber from interfering with the operation of the coin collect magnet 13 by rotating his calling dedifl erence in the operation of the switches would be that the'back bridge relay in the connector would not pull up to reverse the battery to the calling line and-therefore the relay 27 in the group of relays D would not be energized. In this case the relays 28, d4, 48, 45, 51 and 57 will all operate in exactly the same manner as in the case of the answered call except that when relay 4:8 falls back the impulse of current sent to the line circuit to operate the magnet 13 comes from the high voltage negativebattery M instead of battery K. Battery M supplies current of such a direction as to cause magnet 13 of the coin collector to tilt its armature in the opposite direction to send the deposited coin down the refund chute to the calling subscriberand to restore the springs 10, 1-1 and 12 to their normal positions.

Referring now to- Fig. 3 of the drawings 1 have shown a manual cord circuit F of a standard type which is for use with calls from manual lines such as B to other manual lines or through connector switches such as H to subscribers such as A (Fig. 1) which may be in the same or in a different is manual'to automatic pay station,- means must be provided for operating the coin coilector on the called line in case it is desired to reverse the charges. 0f course, the

manual subscriberwould be charged in the ice BBO

exchange. In a call of this last type, that Gil subscriber B to the subscriber A through the cord circuit F and connector H, when the charge is reversed.

When the subscriber B lifts thereceiver the Operator is signaled in the usual manner by means of the lamp 81 which is extinguished when the operator inserts the plug into the jack'of the calling line, the operator then throws her listening key, obtains the wanted number and inserts the calling plug into a jack leading to an idle connector switch such as H which has access to the multiple normals of the line A (Fig. 1). The line relay 82 of the connector H 'is energized'in series with the coil oft-he cord circuit and the lamp 841: of the cord circuit is lighted through the springs 85 of relay 86. The operator then throws her calling device key to bridge the calling device 87 across the cord circuit in series with the line relay 82. Relay 82 closes the circuit of relay 88 which, prepares the circuit of slow relay 89 and vertical magnet 90 and closes the springs 91, 92.and 93into contact. lVhen the calling device is operated for the first digit of the called number the line relay 82 operates to close the circuit of magnet 90 and relay 89 in series to step the wipers of the switch to the desired level of the bank. Soon after the impulses 'gagement with the normals 96, 97 and '98 of the line A. Relay 94 remains energized for a short time after the rotary impulses cease to hold the private wiper in connection with the busy relay 99 so that if the called line is busy the relay 99 will; operateto connect a busy tone to the operator. llf'the line is idle net 21 of the called line to battery. 100 energizes and locks energized to cut the however, relay 94 upon fallingback, closes a circuit for the upper winding of relay 100 from ground at springs 91 and 93 through said winding and through relay'22 and lgiagcalled line through to the ringingcircuit and ring out 01f relay 101. When the called subscriber answers. relay 101 energizes and completes the circuit ofth'e back bridge relay 86, which also energizes in series with the-called line toopen the sprin 85 .to extinguish the lamp 84: to inform t e oper- .ator that the called man has answered.

The special relay 102 in series with the line relay is a polarized relay which does not operate with the usual battery potential, but only with a battery of 110 volts of either polarity. Now, when the called subfirst informs him that the calling partyhas nomination for the call.

meaaae asked to have the charges reversed and requests him to drop a coin of the proper de- The called subscriber deposits the coin and the operator then throws her key 103 to energize the relay 104, thereby connecting the positive high voltage battery 105 out over the trunk line and through relay 102 to ground.- Relay 82 is held energized and relay 102 operates to attract its armature in such a direction as to close the springs to connect the high voltage battery 108 out over the lower talking conductor to conductor 97 through springs 7 of the calling device of station A, springs 11 and 10, springs 17 and 18, and magnet 13 to ground, thus depositing the coin. The operator then restores the talking circuit and allows the two subscribers to converse in the usual manner.

Should the operator be unablla to get the calling party after the called man has deposited the coin or for any other reason desire to refund the coin after it is deposited by the called man she may throw the key 110 to connect the reversed high voltage battery to relay 102 which in turn projects negative high voltage battery to the coin collect magnet of the called line to operate said magnet in a direction to refund the charge. It will be understood also that this system .readily adapts itself to free service calls, that is a connector such as that shown in U. S. Letters Patent 1,269,245, granted June 11, 1918, to Albert Andersen, may be used in place of the connectorH, (Fig. 2),-which connector when used to call certain subscribers will not reverse the battery and.

therefore in all such calls the coin will be refunded even when the called man answers. In Fig. 4 I have shown a modification of my invention which may be used inpurely automatic systems without departing from the spirit of my invention. At A I have shown a standard common battery station having a pay-station the same as that described for station A, Fig. 1, except that the magnet 13 is bridged acrossthe line after the receiver is hung up and when a'coin is deposited, the springs 200 preparin the circuit of magnet 13 when the coin is deposited and springs 201 opening a shunt about the calling device. When the receiver is-hung up the relays D which are the same'as the relays -D, Fig. 1 operate to connect the booster battery in series with the line and 'to ground through springs 202 closed byrelay 57. I have shown only a portion of the relays D as the rest are exactly like the rela s D, the only change being the addition of t o springs 202. When thereceiver is restored the magnet 13' which is of very high resistance allows the release of the switches and is operated in series with the line circuit from the high voltage batteries to either refundor collect.

It will be seen therefore that I have provided a very efiicient means for controlling a coin collector of the coin first type in an automatic or semi-automatic system and one which is very reliable in its action.

Having fully described and ascertained the features and aspects of my invention, what I consider to be new and desire to have protected by Letters Patent will be pointed out in the appended claims.

What I claim as my invention is:

1. In a telephone system, a line, a pay-station for said line, automatic switches for establishing a connection from said line to another line, a battery of one voltage for controlling said switches, said pay-station nonresponsive to current from said battery in either direction, two other batteries, automatic means for preparing circuits of two different characters from said other batteries for said pay station, the circuit prepared depending upon the completion or the noncompletion of the call, and means controlled by a calling subscriber for completing the circuit prepared to either collect or refund the coin.

' 2. In a telephone system, a line, a pay-station for said line, automatic switches for switching a connection from said line to another line, a battery of one voltage for controlling said switches, said pay-station nonresponsive to current from said battery, two other batteries, automatic means for preparing circuits of two different characters from said other batteries for said pay-station, the circuit prepared depending upon the completion or the non-completion of the call, and means controlled by a callin subscriber after the termination of the call orcompleting the circuit prepared to either collect or refund the coin. V

3. In a telephone system, lines, coin collectors for said lines, a switch for each line, trunk lines common to said lines, means for operating said switch to extend a talking circuit from a line over one of sald trunk lines to a called line, a magnet for said calling line for COntIOlliDg the coin collector, a battery for controlling the automatic switches to extend the connection, sald magnet non-responsive to current from said battery, a relay in said trunk line in series with the callin line for determining whether the coin is to e collected or refunded, and means controlled by the calling subscriber for con-' 'necting apositive or negative battery to said magnet to operate the same to either collect or refund the coin depending upon the relay. a. In a telephone system, lines, coin collectors for said lines, a switch for each line,

trunk lines common to said lines, means for operating said switch to extend a talking circuit from a line over one of said trunk lines to a called line, a magnet for said calling line for controlling the coin collector, a bat-.

.magnet to operate the same to either collect trolled by the calling subscriber for connecting a positive or negative battery to said or refund the coin depending upon the relay.

5. In a telephone system, a line, a coin collector therefor, a magnet .for controlling said coin collector, twobooster batteries, means for extending a talking circuit from said line to a called subscriber, an electropolarized relay controlled in one manner in a successful call to prepare a circuit for said magnet to one battery, and in another mannor in an unsuccessful call to prepare a circuit for said magnet to the other of said batteries, and means controlled by the calling subscriber for completing whichever one of said circuits that is prepared to operate said magnet vto either collect or refund the coin depending upon which battery is connected thereto.

6. In a telephone system, a line, a coin col lector therefor, means for extending a talking I circuit therefrom to a called subscriber, a relay in series with thetransmitter circuit of the calling line for determining whether the coin is to be collected or refunded, and a magnet at the coin collector automatically controlled over the talking circuit by an in- 109 creased flow of current to collect or refund the coin as determined by the said relay.

7. In a common battery telephone system,

a pair of telephone lines, means for connect- N ing the two and for establishing a flow of current through conductors in the-connecting circuit, a toll assessing device for assessing toll for the connection, said device including an operating electromagnet, said magnet nonresponsive to said flow of cur- 1w rent, means for causing an increased flow of current in the line in either of two directions to cause the operation of the magnet, and electromagnetic means in the battery supply circuit of the calling subscriber under the control of the called subscriber for rendering said last mentioned means efi'ective in theproper direction to assess a toll.

8. In -'a telephone system, a calling telephone, a line therefor, automatic progressively movable switches for extending connections therefrom, another calling line hav 'ing means for extendin a connection to said ing an operating magnet connectedto said line, means in either connectionfor suplying-talking current to said first line s .it meat for talking purposes but inscient for optee nections therefrom, another calling line having means for exten ding a connection to said first line, a toll assessing device for assessing toll for calls to or from said first line, said toll assessing device having an operating magnet connected to said line, means in either connection for supplying talking cur- ,rent to said line sufiicient for talking purposes but 'insuflicient for operatively energizing said operating magnet, and means 1n oneof said connections for automatically increasing the flow of current through said magnet for refunding toll.

10. In a telephone system, a line, a coin collector therefor, means for extending a talking circuit therefrom to a called subscriber, a relay having one winding in said talking circuit and a second winding in a holding cir'cuit, said relay. for determining whether the coin is to be collected or refunded, and a magnet at the coin collector automatically controlled over the talking circuit by an increased flow of current to collect or refund the coin as determined by said relay.

11. In a telephone system, a line, a coin collector therefor, means for extending a talking circuit therefrom to a called subscriber, a plurality of relays in series with the calling line, one of said relays for determining whether the coin is to be collected or refunded, and a magnet at the coin collector automatically controlled by another of said relays by means of an increased flow of current to collect or refund the coin as determined by said first relay.

12. In a telephone system, a line provided with a coin collecter, a ma et for controlling said collector, a calllng device for the line normall inoperative, means coni trolled by the com when deposited for rendering the calling devlce operative, a relay controlled by the completion of a call extended from the line by means of the calling device for determining whether the coin is to be collected or refunded, and a relay in series with said first rela controlled by the aging up the recelver for causing the operatlon of said magnet as predetermined.

13. In a tele hone system, a line, a coin collect device or said line, a trunkline, a

connector switch, a relay in said connector switch, means for extendin a continuous metallic connection from said line to said connector switch, means. for operating said connector switch to extend a connection to a called line, a magnet for said deaesaa ae vice, a relay included inthe said metallic connection controlled by the called subscriher to prepare an operating circuit for said magnet, and means in said trunk line controlled by the calling subscriber for causswitches including a connector switch for extend ng a connection irom sald l1ne to a called line, a magnet for operating said pay station, said magnet non-responsive to battery currents. used for operating said swltches, high potential batteries for operating said magnet, and a relay in the circuit or the calling line controlled by a relay in the connector switch for determining the manner in'which said magnet is to be operated. p

15. In a telephone system, a line equipped with a pay-station device, a series of automatic switches including a connector switch for extending a connection to a called line, a magnet for said'pay-station device nonresponsive to a normal fiow of current in said connection, a batte of high potential, a relay in the calling l1ne for closing one point in a circuit between said battery and said magnet, said relay controlled by said called line through the medium of another relay in said connector switch, and means controlled by the calling line for closin said circuit to cause the operation of sai agnet. 16. In a telephone system, a line, a coin collect device therefor,a trunk line, means for extending a connection over said trunk line to a called line, a magnet for said device by said calling line for causing the prepared circuit to be completed to cause the operation of said magnet. v

17. In a telephone system, a calling and a called line, a train of automatic subscriber controlled switches for connecting said lines, a trunk line included in the connection between two of said switches, a coin collector at the station on the callin line having a magnet non-responsive to t e batteryfused for controlling said switches, a high voltage. battery, a relay in one of said switches for reverslng the direction of current flow in said trunk line when the called party .answers, a polarized relay responsive to such currentreversal 'for preparin a control circuit for said magnet inclu ing said high voltage battery, and, a relay individual to said trunk line responsive to the replacement of the receiver at the calling station for completing said circuit to operate said. magnet and collect a deposited coin. V

18. In a telephone system, a calling and a called line, means including a line switch individual to the calling line, a trunk line accessible to said line switch, and a first selector inwhich said trunk line terminates for connecting said lines, a paystation at the station on the calling line, means responsive to the replacement ofthe receiver at the calling station for releasing said first selcctor and for completing a circuit over the calling line and a portion of said trunk line to control said paystation, and a holding circuit for maintaining said line switch in operated position to prevent the premature opening of said paystation control circuit.

19. In a telephone system, a calling and a called line, means including a. line switch individual to the calling line, a trunk line accessible to said line switch, and a first selector in which said trunk line terminates for connecting said lines. a holding circuit eitending back through the first select-or, .over aconductor of said trunk line for maintaining the line switch and select-or in operated position, a paystat-ion at the station on said magnet being nonresponsive to the batlery used for operating said switches, a high voltage battery, a quick relay and'a slow-- acting relay maintained energized during conversation, a circuit between the said magnet and high voltage battery including break contacts on'saidquick relay and make con- 7 part-y hangs up, thereby supplying perat- 1ng current to said magnet for an lnterval after the release of the 'quick acting relay and before the release of the slow acting relay. r

21. In aj-telephone system, a calling and acalled line, a train of automatic switches for connecting said lines, a trunk line included in the connection between two of said switches, a coin collector at the station on the calling line having a magnet non-responsire to the battery used for controlling said switches, a high voltage battery, a relay individual to said trunk line controlled by the called subscriber to prepare a circuit for said magnet including said high voltage battery and the two talking conductors of the-calling line in series, and a relay retacts on said slow relay, and means for de-' energizing bothi relays when the calling I sponsive to the replacement'of the receiver at thecallin -station forcompleting said circuit to col ect a deposited coin.

22. In a telephone system, a line, a pay: station for said line, automatic switches for establishing a connection from said line to another line, a battery of one voltagev for ,controlling said switches. said paystation nonresponsiv e to current from said battery in either'directlon, means forsupplylng positive and negative currents of higher voltage than the voltage of said battery,

automatic means for preparing two difl'erent circuits for supplying said .high'voltage currents to said paystation, the circuit prepared depending upon the completion or the noncompletion of the call, and means controlled by the calling subscriber for completing the circuit prepared to either collect or refund the coin.

Signed by me at Chicago, Cook County, Illinois, this 12th day of May. 1919.

' I TALBOT G. MARTIN. 

